Showing papers by "David Communi published in 2008"
TL;DR: It is demonstrated here that neutrophil‐derived proteinase 3 (PR3) and mast cell (MC) chymase are involved in the generation of specific chemerin variants, which are inactive, as they do not induce calcium release or DC chemotaxis.
Abstract: Chemerin is a potent chemotactic factor that was identified recently as the ligand of ChemR23, a G protein-coupled receptor expressed by mononuclear phagocytes, dendritic cells (DCs), and NK cells. Chemerin is synthesized as a secreted precursor, prochemerin, which is poorly active on ChemR23. However, prochemerin can be converted rapidly into a full ChemR23 agonist by proteolytic removal of a carboxy-terminal peptide. This maturation step is mediated by the neutrophil-derived serine proteases elastase and cathepsin G. In the present work, we have investigated proteolytic events that negatively control chemerin activity. We demonstrate here that neutrophil-derived proteinase 3 (PR3) and mast cell (MC) chymase are involved in the generation of specific chemerin variants, which are inactive, as they do not induce calcium release or DC chemotaxis. Mass spectrometry analysis showed that PR3 specifically converts prochemerin into a chemerin form, lacking the last eight carboxy-terminal amino acids, and is inactive on ChemR23. Whereas PR3 had no effect on bioactive chemerin, MC chymase was shown to abolish chemerin activity by the removal of additional amino acids from its C-terminus. This effect was shown to be specific to bioactive chemerin (chemerin-157 and to a lesser extent, chemerin-156), as MC chymase does not use prochemerin as a substrate. These mechanisms, leading to the production of inactive variants of chemerin, starting from the precursor or the active variants, highlight the complex interplay of proteases regulating the bioactivity of this novel mediator during early innate immune responses.
90 citations
TL;DR: The data suggest an involvement of HDGF during the initiation phase of the apoptotic process downstream from an initiator Caspase and a regulation of this protein by phosphorylation in the nucleus.
Abstract: We were looking by a proteomic approach for new phospho-proteins involved during the early steps of the TNF + cycloheximide (CHX)-induced apoptosis-preceding mitochondrial membrane permeabilization-of endothelial cells (BAEC). In the present study, we observed on the autoradiography from 2D gel of (32)P-labeled samples a string of proteins undergoing a complete dephosphorylation after 1 h of stimulation with TNF + CHX-while mitochondrial membrane permeabilization was observed after 3 h-identified the different spots by mass spectrometry as one and only protein, HDGF, and confirmed the identity by western blot. The intensity of the 2D phosphorylation pattern of HDGF was correlated with the amount of apoptosis induced by TNF + CHX and TNF or CHX alone and this event was inhibited by the Caspase specific inhibitor zVADfmk. Moreover the TNF + CHX-treatment did not affect the nuclear localization of GFP-HDGF. Taken together, our data suggest an involvement of HDGF during the initiation phase of the apoptotic process downstream from an initiator Caspase and a regulation of this protein by phosphorylation in the nucleus.
8 citations
Patent•
01 Aug 2008
TL;DR: In this paper, a G-protein coupled receptor and a novel ligand were proposed for the identification of candidate compounds which modulate the activity of the G-Paired receptor, as well as assays useful for the diagnosis and treatment of a disease or disorder related to the dysregulation of G protein coupled receptor signaling.
Abstract: The present invention relates to a G-protein coupled receptor and a novel ligand therefor. The invention provides screening assays for the identification of candidate compounds which modulate the activity of the G-protein coupled receptor, as well as assays useful for the diagnosis and treatment of a disease or disorder related to the dysregulation of G-protein coupled receptor signaling.
1 citations
Patent•
13 Mar 2008
TL;DR: In this article, methods, reagents and kits for detecting of formyl peptide receptor like-2 (FPRL2) polypeptide activity in a sample and identifying agents which modulate poly peptide activity.
Abstract: The present invention relates to methods, reagents and kits for detecting of formyl peptide receptor like-2 (FPRL2) polypeptide activity in a sample and identifying agents which modulate polypeptide activity. It further relates to antibodies raised against FPRL2. It further relates to substances for preventing, treating and/or alleviating diseases or disorders characterized by dysregulation of FPRL2 polypeptide signalling.
1 citations
Patent•
13 Mar 2008
TL;DR: In this article, methods, reagents and kits for detecting of formyl peptide receptor like-2 (FPRL2) polypeptide activity in a sample and identifying agents which modulate poly peptide activity.
Abstract: The present invention relates to methods, reagents and kits for detecting of formyl peptide receptor like-2 (FPRL2) polypeptide activity in a sample and identifying agents which modulate polypeptide activity. It further relates to antibodies raised against FPRL2. It further relates to substances for preventing, treating and/or alleviating diseases or disorders characterized by dysregulation of FPRL2 polypeptide signalling.